AC 43.131B 8-31 Fuel Lines and Fittings, para B "Routing". I cant copy and paste the section cause its a .pdf, but you can search for it if need be. You can run them together, but read the para for clarification on exactly how that is to be done. For sure, separation is the preferred method.
Additionally, Section 8 Wiring Installation, 11-96, para W (change 1) has a slightly more expansive and perhaps somewhat contradictory take on it as noted with the words "where practical".
Section 11-126 Flammable fluids and gases has similar wording as 11-96 in Section 8, but includes a picture of a wire bundle and fuel line together....
There maybe others, but thats what I found in a quick search. I did this as I'm also currently running wing wires and have tip tanks with fuel lines running in similar areas, so it was a good question that you asked......thanks.